Means for cushioning hydraulic pressure in feed-pipes.



f R. D. JOHNSON. I MEANS E OR GUSHIONING HYDRAULIC PRESSURE IN FEED PIPES.

' APPLIOATION FILED JUNE '19, 1908.

@62,3551 Patented June 21,1910.

RAYMOND D. JOHNSON, OF ALBANY, NEW YORK.

MEANS FOR CUSHIONING HYDRAULIC PRESSURE IN FEED-FIDES.

Specication of Letters Patent. Patented June-21, 1910 Application filed .Tune 19,1908. Serial No. 439,319.

. To all whom 'it 'may concern.:

Be it known that I, RAYMOND D. JOHN- soN, a citizen of the United States, residing at the city 'of Albany, in the county of Albany and State 'of New York, have invented certain new and luseful `Improvements in Means for Cushionin Hydraulic Pressure in Feed-Pipes, of which-the following is a specification.

My invention relates to devices for assisting turbine speed regulation by pressure control in water powers with long pressure pipes and high velocities, and the object of iny invention is to provide a means for cushioning hydraulic pressure in feed pipes, together with such other elements and combinations as are hereinafter more particularly described. I accomplish these .objects by means of theapparatus diagramrnatically illustrated in the accompanying drawings,

in which:

erable distance from the power house, a

. diiiculty arises when the load on the turbine changes,`lwhen the demand for van increase of water is'made. The sudden requisition made -onthe feeder for an additional` supply, which can only be obtained by accelerating the velocity of the water in .the

aqueduct, causes a wave or surge to be transmitted through the aqueduct, re-

sulting in water hammer 'or-other disagreeable and objectionable phenomena. The action ofthe wave interferes with the steady discharge of the water and causes an intermittent Iexplsosive discharge, depending, of course, in its occurrence and intensity, upon the degree of the demand made on the feeder by the turbine. After the wave has passed through-the -aqueduct and sulicient time has -elapsed to enable the velocity t0 up,

the inflow will continuev to increase above the demand therefor, and the result is a tremendous variation in pressure, and if bypass pipes are employedk or other escapement devices used, adischarge will take place through these by-pass pipes and escaping ducts which is not only'extravagantly wasteful, but also so slow in correcting evil as to f injuriously ai'ect the turbine speed regulation.

For the purpose of doing away with 'the objections, inconvenience and wastefulness of the present system l have provided an elective, ellicientand economical means for taking care of the change-in the demand for water made by the power generating apparatus and su plying or storing the same gradually, speedlly and constant y without the objectionable Water hammer accompanying.

I illustrate by the drawing one means of accomplishing this result in which the reservoir, A, is tapped by the feeder pipe craqueduct, B, which has the drop portion, C, leadmg to the power house D and discharge E.

The proportions shown in the drawing are not intended to be necessarily correct as some parts are exaggerated forthe purpose of illustration. l place in the equeduct, B, just above the drop portion, C, a stand pipe, F, which projects into a surge tank, G, in which the water is below the height of the water in the reservoir by an amount equal to the friction loss in the aqueduct, B. The stand pipe, F, extends above the water in the surge tank. In the' stand pipe, F, near the bottom of the surge tank I place a series of restricted openings, The stand .pipe

may, however, be either within or without tank, G, will be delivered to the power house. l

Atthe same time a wave wi :proceed f through theA feeder, B, toward the reservoir,

A, 'but it will be. subjected to v.the quietirl constantly vand in the proper proportions to Y or reacting influence of the supply delivc the demand made by the power house through the restricted openings, H, in the stand pipe. Before the water in the surgevr tank has reached the top of the openings,l

H, in the stand ipe, (the openings, H, being arranged regar in in roperproportlon to the length of the fee er, 'the velocity of the water supply therethrough 'and the area of the surge tank), the velocity of water in the aqueduct will be fairly constant and suitable tothe increased demand. Any increase of water .occasioned by the increased velocity, resulting from the demand for more water, will be delivered through the said restricted openings, H, properly proportioned, as

. aforesaid, to the surge tank and when the tank G, an be attamed in the use of the tank K for the feeder C that could be obtained in the use the power house the reverse operation will' take place, and the excess water will be automatically, quietly stored for future demands.

I have shown in Fig. 2 a tank, K, connected with 'the feeder, C, near the power house, D, in which I do not place a stand pipe necessarily, but arrange for the re-y stricted passa e of the water in the tanky through the dlschar e, L, in the feeder, C. The tank, K, is supp ied with water, M, and

air under pressure. It is a` parent that the.

same effect may be produce .onfthe water in the feeder, C, and in the surge tank by the action ofthe proportioned discharge from tank, K, that 1s produced on the water in the feeder, B, and in the reservoir by the ac# tion of the roportioned discharge from the d) the same beneficial results will of the tank G for the feeder B. In either o case the action on the contents of the tank pot.

an additional loa the period that the velocityr of How in theV occasioned by the sudden demand made by the power generating apparatus or'a sudden rejection of water due to a dro in the power demand will be like that o 'a dash- It will be noted that in each of the devices G and K,l the properly proportioned discharge openings from the surge tank into the feeder, will provide a quantity of water suilicient to suppl the demand produced by dy at the power-house during main feeder is accelerating because of the difference of head calsed by the sudden lowering of level in the stand-pipe F,for`of pressure in the conduit adjacent to tank K.

t will be further noted that when there is,

their size and number atthe power-house, a rejection of water due todecrease of load, then provision is made, not only for storing excess water, but for retarding the velocity of flow in the feeder by an increase of pressure head in either form of surge tank at a rate more rapid than the rate 'of change of water level 1n the tank. Thus in the tank K, owing to the shape given to the discharge L, there is permitted a much more rapid inflow from the feeder C to the tank- K, than outflow from the tank K to feeder C, and in the tank G the excess water will rise freely and rapidly in the com aratively small stand-'pipe F. There is differentiation between what may be termed pressure water and stored water in the same receptacle, the stored water7 being permitted to iow from the surge tank mto the feeder at a rate sufficient to supply all temporary demands, while the pressure water can rapidly and eliciently establlsh in the surge tanks the necessary differences of level relative to that of the water-supply,

lto accelerate or retard to the desired degree the velocity of water in the feeder by lthe time when the capacity of the tank is used up and without the possibility of dangerous surging. By the use of this dilferentlal principle there results not only an efficient damping of the surge waves, but a surge tank may be used of much smaller dimensions than an ordinary stand-pipe, alldwithusa out the danger of continued surging 1n the system.

What I claim as my 'invention and desire to secure by Letters Patent is: l

1. The combination with an elevated reservoir, a` water-wheel, and a conduit connecting the same, of a surge tank having an open connection to the conduit, means for per' mitti'ng a restricted flow therethrough from the tank to the conduit, and means arranged to permit a relatively ra id variation of pressure-.head in such con uit as compared tothe rate tank. i

2. The combination with a conduit ada t- Aed to convey iuids under pressure-head, o a

surge tank havin an open connection to the conduit, means o flow therethrough from the tank to the conduit and means arranged to permit a relatively raid variation of pressure-head in such con change of water level in such tank.

3; A surge tank having an opening ada ted for connection to a conduit, means or pxermitting a restricted iow therethrough om the tank to the conduit and means arranged to permit a relatively rapid variation of pressure-head in such conduit as compared to the rate of change of water level in such tank.

of change of water'level in such I r permitting a restricted uit as compared to the ratev of 4. The combination with a conduit of a,

stanppe connecte thieto and a surge n testimony whereofI have aiixed my tank 'lnnectex to the'stai-pipe. d t signature in presence of two witnesses.

5. e ':om inatomwit a vcon ui o a w stand-pipe"connected4 thereto,`anc 1-a ,sur e RAYMND D' JOHNSON 5 tank surrounding the standpipe, said stan Witnesses v pipe having ports connectmg it; with the v FREDERIGK W; CAMERON, surge-tank. Lo'l'rm Pmon. 

